Field of the Disclosure
The present disclosure generally relates to controlling lost circulation in a well during drilling with a drilling fluid and reducing water production during production from the well. More specifically, embodiments of the disclosure relate to lost circulation materials (LCMs) and well treatment fluids.
Description of the Related Art
Various challenges are encountered during drilling and production operations of oil and gas wells. For example, fluids used in drilling, completion, or servicing of a wellbore can be lost to the subterranean formation while circulating the fluids in the wellbore. In particular, the fluids may enter the subterranean formation via depleted zones, zones of relatively low pressure, lost circulation zones having naturally occurring fractures, weak zones having fracture gradients exceeded by the hydrostatic pressure of the drilling fluid, and so forth. The extent of fluid losses to the formation may range from minor losses (for example less than 10 barrels/hour ((bbl/hr), also referred to as seepage loss, to severe (for example, greater than 100 bbl/hr), or higher, also referred to referred to as complete fluid loss. As a result, the service provided by such fluid is more difficult or costly to achieve.
Such lost circulation can be encountered during any stage of operations and occurs when drilling fluid (or drilling mud) pumped into a well returns partially or does not return to the surface. While de minimis fluid loss is expected, excessive fluid loss is not desirable from a safety, an economical, or an environmental point of view. Lost circulation is associated with problems with well control, borehole instability, pipe sticking, unsuccessful production tests, poor hydrocarbon production after well completion, and formation damage due to plugging of pores and pore throats by mud particles. Lost circulation problems may also contribute to non-productive time (NPT) for a drilling operation. In extreme cases, lost circulation problems may force abandonment of a well.
In another example, after a well is completed and becomes a producing well, water production from the well may cause significant economic drawbacks. High water production rates may cause a reduction in well productivity, an increase operating expenditures, and can completely block production from wells. Consequently, controlling and eliminating unwanted water influx into oil or gas wells is a major concern of producers. The water produced in a well may be the result of a water-producing zone communicating with the oil or gas producing zone by fractures, high-permeability streaks, fissures, vugs, or the like. Water production may also be caused by occurrences such as water coning, water cresting, bottom water, and channeling at the wellbore. Such water production is typically produced at the expense of oil or gas recovery, and, in severe cases, the water influx may be so great that oil or gas production is choked off completely.